Explosives packaging



Powder Company, wilmiilgton, Del., a Corporation of Delaware Filed' July 25-, 1957, Se'r. N'o. 674,102 1 Claim. (Cl. .ss-d) My invention 'consists' in anovl method of e'nca'sing' an' xp'les'iv' body in [nem] foil. V v

More Specifically my inv'ent'io'n comprises the packagin'g of an' explosive pellet in metal for use in ammunit The novel ackaging of lead and booster pelleshof present invention provides ati' in expe'nsie b'ut 'efictive package for pellets of explo'sive"material' thuseli'r'ninating dusting, cracking and chipping during subsequent handling op ftiohs". v i

In ammunition loading it is common practice to cornpress exploi'ves into pellet form for ease in hanrlling in 'the leading area. During the handling of the explosive pellets between the powder preparing area and the loading area, it is diicult to -avod chi'pping, cracking, fiaking or dusting. The chipsand powder accompanying the pellets present both aneXplosion and health hazard lt is therefore an object of the present invention to reduce the aforesaid explosion and health hazards.

Also in the loading of explosive components into ammunition it is difficult to prevent explosive dust from becoming lodged on metal parts of the ammunition assembly and when the deposits are on surfaces which 'are mated with other surfaces there is present the danger of accidental explosion during the assembly operation. This is particularly true if the mating surfaces are to be screwed or crimped together. It is therefore, an object of the present invention to provide an explosive pellet with which the danger of accidental explosion during the assembly of the Component parts of military projectiles is minimized.

It is well known that some explosive materials are toxic to certain individuals and may Cause dermatitis upon contact with the skin. The present invention of encasing explosive pellets in metal produces pellets which are not subject to fiaking, chipping and powdering, thus the danger of explosive material contacting the skin of personnel handling the explosive is largely eliminated. It is therefore an object of the present invention to provide a package which prevents dermatitis due to the handling of explosive material by personnel assembling ammunition components.

Another undesirable consequence of the necessary handling of explosive pellets is that each chip and particle removed from the pellet subtracts from the amount of explosive loaded into the ammunition. While in some instances the loss of explosive due to chipping, etc., may not be significant, the loss may be critical in lead or detonator elements. If a booster pellet significantly reduced in size due to chipping, dusting, etc., is loaded into a fuse it could result in a low order detonation or malfunction when the lead is fired. It is therefore an object of the present invention to provide a pellet With which the aforesaid malfunctions which are the result of an insuficient amount of explosive in the lead detonator or booster charge of an explosive train are largely eliminated. Pellets encased in metal as hereinafter described can be loaded into fuses, boosters or projectiles with little or on danger of lost powder lodging in parts or Z,940,35Z Ptented June 14, 1960 2. on iiidivilal perforniih the assembly' Operations; :ao-'reove'r there is little' likehod of malftictiorii'g' of' the explosive train because of insufficien't pwdr' in" the' lead' booster or' detnato el'emehti Theprese'n't' inventioii is a-metlio of enc'asiitg* air-existe- -sivebody in rri'e't'al 'Sheet which c'ompris'e's' fo'ring saidme'ta'l through a fo'rining die co'nfo'i'iing substan lally 'to the shape of Said ex'plosive body; the ex'plsivebody serv# ing as' a male member' of' the' die' assembly: Thereby' the: metal ericasesa desird' portioti'f the eirplosivebody' and takes" thesliape of' said Body:

In' the drawin'gs:

Figure" 1 is a diagranimatic cross-section of i adie' assembly showing a'I'i' e plosiv'e' pellet and thin s'h'e'e't' of nit'al prio to blking and" 'frrni'nga z j Figure 2 is a diagrammatic cross-section of' a die as'sern bly showing the blnki rig pertin- A Figure 3 is'a diagrmriatic i'oss-ec'tinof a dieasembly showing'the'fo'rmifig opertinwith the' rfe'talwi'ap per being cold d'rawn' about the' expl* ve pellet. v

Figure 4 is a diagrammatic cross= Ii of adie assetrr bl' showing* the' completed in' dperafin; with* the punching' member' and e'xplbive' pellet intheir most dwnwa position; V i V, Figre 5' is a cross-section' showing' a ,lead cup' and' booster cup containing their 'respective 'xplosive pellets pec'ificlly illIi'st-'ra't'e' the' al'll V of bh t' the" packaging''f 'eitplsiv booster pellet 10 which may, for example, be pressed tetryl. The die assembly 7 includes a double-action die comprising -a punching member 14 and a blankng member 15 operating on a cutting matrix 8 and a forming matrix 12. A thin Sheet of metal 6, for example, aluminum Sheet of 0.01 inch thickness, Supports the explosive pellet 10 between the punching member 14 and the female portion of the die assembly 7 as shown in Figure 1.

In Figure 2 the position of the die assembly 7 is shown after the blanking member 15 has moved to its most downward position after having' blanked the metal Sheet 6. The punching member 14 and the explosive pellet 10 are moved downwardly With the blanking member 15. The arrows in the various figures indicate the motion of the parts.

Figure 3 shows the punching member 14 moving downwardly. The metal Sheet 6 forms about the explosive pellet 10 which acts as the male member of the die assembly as it is forced into the perforation 16 of the forming matrix 12.

Figure 4 shows the punching member 14 and the explo- Sive pellet 10 in its most downward position with the metal Sheet 6 cold draWn about and completely enveloping the bottom and side surfaces of the explosive pellet 10. After completion of the forming operation the pellet and it-s encasing cup are removed from the die for capping and subsequent assembly into the ammunition.

The assembled lead cup and booster cup containing the explosive pellets can be readily handled and ncorporated into the ammunition as desired. V

The specific embodiment of the present invention shown in Figures 1 through-'4 have described the packaging of an explosive pellet to be usedas a booster eley As shown in Figure 5 a metal cap 6' has been drawn 'v about lead pellet 10' by methods such as just described and the lead element is crimped to the top of booster pellet 10 after it has had metal 6 drawn about it. The fabrication'of units as described Will reduce the' hazards hereinabove mentioned and at the same time'provide better quality ammunition. j 3

The metal used for drawing about explosive pellets in accordance with the present invention may be of any gauge which can be. readily worked with the equipment available and the cohesiveness and hardness of the explosive pellets being encased. Itshould however not be So thin that it is tom in the process of-forming and that the operation becomes merely one of Wrapping and folding rather than drawing. V Gauges between 0.002 and 0.020 inch have been found satisfactory for aluminum. Similar -gauges of other metal sheets may be used.

The'metal stock 'may be any which is conveniently drawn. Aluminum, tin, leadvand Copper are examples of suitable materials.

The explosives may Iikewise cover a large range. The pellets maybe formed of Compressed granules or powder or may be cast. Suitable compositions include tetryl, trinitrotoulene, pentaerythritolv tetranitrate, amatoland cyclonite, for example.

. The present invention has been described as 'a method of ackaging an explosive element using a solid slug or pellet as the draw punch in a cuppingoperation. On shallow draws Such-as encasing of the booster element the cup may be drawn from a fiat-metal blank in one operation as illustrated in the specific embodiment of ,the present invention. It is however, within the Scope of 'the' present invention to perform die Operations requiring deeper draws. In performing -deep cup draws one or more preliminary' draws may be required in which case the explosive pellet is used only for the final draw with the preliminary drawing dies being of larger diameter than the explosive pellet.

One advantage of the present inventon is' that it is adaptable to the encasng of a wide Variety of shapes as for example, toruses, cones, prisms, and unsymmetrical shapes.

It is also within the purview of the present invention to provide the complete closure of the encased pellet by inserting a cover in the Open end of the cup and then crimping 01' otherwise securing the metal cup over the cover. V

Having thus described my'invention, what I Claim as new and desire to rotect by Letters Patent is:

A method of enca-sing an explosive pellet in Sheet metal of from about .002" to about .O20" in thickness which comprises placing the explosive pellet in conjunction With the=sheet metal adjacent a forming-dieconforming substantially to the shape of said explosive pellet; passing said explosive pellet in conjunction With the- Sheet metal through Said forming die, Said 'explosive pellet serving as a male member of -a die asesmbly in cooperation with the forming die, and thereby drawing said Sheet metal about thesurface of said explosive pellet.

References-Chet! in the file of this patent V UNITED -STATES PATENTS 1385,543

Grover s Nov. l, '1932 2,809,585 Moses Oct. 15, 1957 FOREIGN PATENTS i 5,482 Great Britain Dec. 14, 1881 745,124 1944 Germany Feb. 26,

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